That’s totally wrong. You can over-specialize, or you can be a jack of two or more trades.
There’s 19 or 20 abilities (whether or not you get a token for level 1 is technically debatable, though unlikely) and 10 abilities per class, with the exception of Operative and Soldier, who have 11, as well as 10 general abilities.
That means if you bought EVERY SINGLE POINT in one class, and EVERY SINGLE POINT in general abilities, you would be one short. The suggestion that you need, or even can use every single point in one class and general abilities is silly. You would have to assume that some are for all intents and purposes mutually exclusive (Cortex Bomb & Downed Fire, for instance, or Molotov & Grenade Shooting).
Once you’ve decided that you might put points into another class, then you start asking the question “how many?” You could have a minor secondary with a split like… 8/8/3, or you could have a major secondary, like 7/6/6.
Then you have the question of “what if you don’t want to specialize,” which presents the question of 3 classes or 4, and how much you want to specialize, and if you want any general abilities at all, so you could decide on 3 classes and still get variations like
5/5/5/5, or 10/4/3/3 with 10 general, or 10/4/3/3 with 1 specialized class and 2 minor secondaries, or you could have 7/6/6 with no general abilities at all.
To suggest there’s only two choices is silly.